The Science of How Air Filters Work

The Science of How Air Filters Work

You already know that the air filter in your heating and air-conditioning system traps toxins and airborne particles — but do you know exactly how it does so? Here’s some air filter science to help you better appreciate the filter’s role and understand the importance of changing it regularly.

How Air Filters Work

Air filters are typically installed in the return duct or in the return air vents in every room to intercept the air flowing into your HVAC system. They consist of crisscrossed fibers of materials such as:

  • Fiberglass
  • Foam
  • Paper
  • Cotton
  • Polypropylene

For every air filter, the space between its fibers is larger than the tiniest particle size that the filter is supposed to remove.

Air filters capture a wide array of contaminants, such as dust, mold, and pollen. By removing these pollutants from the air that’s going to the HVAC system, air filters prevent damage to the system that would’ve been caused by the buildup of dust and debris. They also help you have healthier indoor air.

Clogged Filters

Air filters that are left unchanged for long result in a pressure drop, which is the change in static pressure as air flows through the filters. In simple terms, the pressure drop is how much your filter limits airflow. Continued buildup of particles leads to a high pressure drop.

If you leave a filter unchanged for way too long, particles could fill up the filter to the point where there’s zero airflow. That means your HVAC system is running but not achieving the desired results.

The more your HVAC system pushes itself to suck air through your air filter, the longer it will run and the more likely it is to break down. Changing your filters helps you save money on expensive repairs and on your energy bill.

Filter Ratings

The MERV (Minimum Efficiency Reporting Value) scale rates a filter’s efficacy in filtering the air. The higher the MERV rating, the more effective the filter is at catching airborne particles.

As air filter science shows, your filter works hard to protect the health of your HVAC system and that of your family. Play your part by inspecting it regularly and replacing it when it’s dirty. If you have questions about air filters or other HVAC components, contact Aggressive Mechanical Contractors. We provide a wide range of heating and cooling services to homeowners in Monmouth and Ocean counties.

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